Connecting structure for timbers

ABSTRACT

A joint to connect sawed timber, particularly natural logs which have been turned or shaped to be uniform for making or interfitting logs so as to form watertight joints. The mating ends of adjacent logs are provided with matching half dovetail cores which are perpendicularly insertable in overlapping relation into transverse notches formed around a core in an intersecting log. The half dovetail cores when inserted together form a core the length of which is appreciably less than the overall width of the timber so that the vertical edges of the timbers on opposite sides of the notches in the intersecting core are tightly drawn against the adjacent opposite sides or faces of the intersecting timber. The core formed by the half dovetail cores is reduced both in height and width and the height of the completed core is less than one-half of the height of the timber and is equally spaced from the opposite longitudinal edges or sides of the timber. The core in the intersecting timber is substantially the same dimensions and location relatively to the intersecting timber as the combined half dovetail cores.

United States Patent 1 Hall et al.

[ Apr. 2, 1974 CONNECTING STRUCTURE FOR TIMBERS [76] Inventors: Gilbert D. Hall, 1940 Montecito Ave., Santa Rosa, Calif. 95404; Paul Purpura, 519 Madrone Dr., Yuba City, Calif. 95991 [22] Filed: Mar. 20, 1972 21 Appl.'No.: 236,131

[52] US. Cl. 52/753 T, 403/38l, 403/231, 52/284, 46/23, 46/20 [51] Int. Cl. Fl6b 7/00 [58] Field of Search ..287/20.92 Y, 20.92 J, 2 4V 1 312.95Z l.3c

[56] References Cited UNITED STATES PATENTS 1,357,626 11/1926 Een 287/2092 Y 2,473,917 6/1949 Edwards 287 2092 D x Primary Examiner.lordan Franklin Assistant EXaminerWayne L. Shedd Attorney, Agent, or FirmGeorge B. White 5 7] ABSTRACT A joint to connect sawed timber, particularly natural logs which have been turned or shaped to be uniform for making or interfitting logs so as to form watertight joints. The mating ends of adjacent logs are provided with matching half dovetail cores which are perpendicularly insertable in overlapping relation into transverse notches formed around a core in an intersecting log. The half dovetail cores when inserted together form a core the length of which is appreciably less than the overall width of the timber so that the vertical edges of the timbers on opposite sides of the notches in the intersecting core are tightly drawn against the adjacent opposite sides or faces of the intersecting timber. The core formed by the half dovetail cores is reduced both in height and width and the height of the completed core is less than one-half of the height of the timber and is equally spaced from the opposite longitudinal edges or sides of the timber. The core in the intersecting timber is substantially the same dimensions and location relatively to the intersecting timber as the combined half dovetail cores.

5 Claims, 5 Drawing Figures PATENTEB APR 2 I974 SHEET 1 BF 2 lllnllllh PATENTEDAPR 2 974 3.800.494 sum 2 [1F 2 1 CONNECTING STRUCTURE FOR TIMBERS BACKGROUND OF THE INVENTION Timber joints, especially in building log cabins, were and are an important problem because of not being waterproof or tight enough. In the joints between such logs various complicated structures were attempted such as the US. Pat. Nos. of Tahvonen, 2,040,110 of 1936, Drake 2,416,162 of 1947, Edwards 2,473,01 80f 1949, Jensen 2,712,678 of 1955, Johnson 3,189,950 of 1965, Steiner 3,257,762 of 1966, Lindmark 3,517,417 of 1970 and Mortensen 3,552,079 of 1971, as examples of various approaches to the problem, without solving the problem completely and particularly without providing for the use in log cabins of shorter logs instead of logs of full length for the side of a house as shown in the Tahvonen and Jensen patents.

An object of the invention is to provide a joint whereby shorter logs along the length of a wall of a log cabin can be tightly coupled together, and also where inside partition or room walls across the outside walls can be connected into the middle of the wall of a log cabin or to each other.

Another of the objects of the invention is to provide a joint which permits greater selectivity of the length of the logs in a log cabin, yet provides tight and weatherproof joints, and facility of assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagrammatic broken-away view of part of a log cabin.

FIG. 2 is a perspective fragmental view showing the one form of assembly of logs.

FIG. 3 is a fragmental development view showing the parts of the logs about to be assembled.

FIG. 4 is a perspective fragmental view showing the joint assembly.

FIG. 5 is a perspective fragmental view showing another form of joint assembly.

DETAILED DESCRIPTION FIG. 1 illustrates a general arrangement of a pair of inside walls 1 and 2 joined to the outside wall 3, so as to fasten the splices between the logs of the outside wall 3.

As shown in FIG. 3, at an end of a log 4 is formed a half dovetail core 6 as a block extending substantially from the middle of the end face 7 of the log 4. The outer side 8 of the half dovetail core is at right angles to the end face 7 and parallel with the adjacent longitudinal side face 9 of the log 4 and is spaced inwardly from said face 9. The inner side 11 of the half dovetail core is cut at an angle to converge toward the face 9 and forms the inclined face of the half dovetail. The inner edge 12 of the inclined side 11 is spaced from the end face 7 so as to leave a base 13 on the face 7. The edge 14 of the base 13 is spaced inwardly from the adjacent face 16 of the log 4 the same distance as the spacing of the level of the outer side 8 from the face 9 of the log 4. The mating end of the other log 17 is provided with a half dovetail core 6 exactly the same as heretofore described except that the log 17 is turned over and around axially to bring the half dovetail core 6 into matching relation with the half dovetail core 6 of log 4. An intersecting log 18 is cut away so as to form a joining core 19 in a transverse recess 21. The core 19 is preferably in the middle of the recess 21 equally spaced from the opposite edges of the log 18. The core 19 is about the same height as the half dovetail core 6 and is about equal one-half of the height of the log. The width of the core 19 as well as the combined width of the half dovetail core 6 is less than the width of the log so as to leave a shoulder 22 on each side of the core 19 or the combined half dovetail core 6 and the width of the recess 21 is about equal to the width of the combined half dovetail cores whereby the base portions 13 are concealed within the recess 21 and the adjacent shoulder 22 abuts against the outside face of the log 18.

Along one edge 23 of each log 16 or 17 is a longitudinal central groove 24. Along the other edge 26 of each log 16 or 17 is a suitable tongue 27 tightly fitting into the groove 24 of the next adjacent log. The intersecting log 18 is also provided with a suitable groove 24 and tongue 27 on its opposite edges.

An example of operation is shown in FIG. 4 wherein, for instance, logs 16 and 17 may be considered as longitudinal logs on the outside walls 3, only shorter than the length of the wall 3. Where these two logs l6 and 17 meet, a crosspiece or intersecting log 18 may be provided which log may be a short log or may be the end of an inner wall 1 or 2 provided with the recess 21 and the core 19. The logs l6 and 17 are placed into the top of the recess 22 and against the opposite faces of the core 19 so that the half dovetail cores interlock as shown in FIG. 4. Then another intersecting log 18 is placed over the top as shown in FIG. 2. In this manner the log wall is erected.

Another example of the application would be that the log 18 is considered a long outside log and the recesses 21 are cut for the purpose of intersecting inside walls, in which case log 16 would form the inside wall, while log 17 would be merely a short piece for locking by its half dovetail core 6 the inner wall log 16 in position to the log 18.

Another example of a joint is shown in FIG. 5 wherein instead of the block 19 in the log 18 half dovetail cores 6 are utilized. In other words, the entire intersecting joint consists of half dovetail cores 6.

The herein invention is eminently adapted for forming joints between logs in longitudinal relation, thereby permitting the use of shorter logs spliced together, and it also permits the easy selective forming of joints at the intersections of logs for building walls.

We claim:

1. In a log connecting structure, for a log having longitudinal sides, opposite edges between said longitudinal sides, and an end face at right angles to said longitudinal sides,

a mating end comprising a half dovetail core extended from about the middle of of the end face of the log,

an outer side of said half-dovetail core being at right angles to said end face and being in a plane parallel with said longitudinal sides,

the inclined side of the half dovetail core having an outer edge in the longitudinal center plane of the log and converging from said outer edge toward said end face of the log and toward said outer side of the half dovetail core, thereby being adapted to interlock with a half dovetail core on the mating end of the next log,

said core being of a height about equal to one half of the height of the log thereby forming recesses for gitudinal sides of the log so as to form side recesses for engagement by the adjacent portions of the respective intersecting log.

4. The invention specified in claim 1, and

said intersecting log having a core of the same substantial cross-sectional area and length as the crosssectional area of the combined half dovetail cores.

5. The invention specified in claim 4, and said core of said intersecting log being also divided into matching half dovetail cores. 

1. In a log connecting structure, for a log having longitudinal sides, opposite edges between said longitudinal sides, and an end face at right angles to said longitudinal sides, a mating end comprising a half dovetail core extended from about the middle of of the end face of the log, an outer side of said half-dovetail core being at right angles to said end face and being in a plane parallel with said longitudinal sides, the inclined side of the half dovetail core having an outer edge in the longitudinal center plane of the log and converging from said outer edge toward said end face of the log and toward saId outer side of the half dovetail core, thereby being adapted to interlock with a half dovetail core on the mating end of the next log, said core being of a height about equal to one half of the height of the log thereby forming recesses for interlocking with cores of intersecting logs having similar recesses, and thereby completely concealing said cores in said recesses.
 2. The invention specified in claim 1, and a base of each half dovetail core substantially equal to the cross-sectional area of the combined half dovetail cores and matching the free end of the respective adjacent end of the opposite half dovetail core.
 3. The invention specified in claim 2, and the respective sides edges of the base of each half dovetail core being spaced from the respective longitudinal sides of the log so as to form side recesses for engagement by the adjacent portions of the respective intersecting log.
 4. The invention specified in claim 1, and said intersecting log having a core of the same substantial cross-sectional area and length as the cross-sectional area of the combined half dovetail cores.
 5. The invention specified in claim 4, and said core of said intersecting log being also divided into matching half dovetail cores. 